Machine for destructuring wood chips

Abstract

A chip destructuring and fissuring machine for destructuring wood chips or the like. The chip destructuring machine includes a support frame and two swing assemblies that provide parallel side-by-side squeeze rollers are swing-mounted on the frame to swing the rollers toward about a swing axis and away from one another between active and inactive positions. A drive motor having a drive shaft with a rotational axis aligned with the swing axis is mounted to the support frame, and drive assemblies couple the drive shaft to the rollers for rotating the rollers in opposite directions at the same rotational speed. Co-acting stops are mounted on the swing assemblies and are positioned to define a spacing between the rollers when they are in the active position for squeezing and destructuring of the chips. A biasing mechanism yieldingly urges the rollers toward one another into the active position. The rollers of one embodiment include a destructuring surface defined by a plurality of criss-crossing V-shaped grooves none of which are parallel to the respective roller's axis of rotation. The criss-crossing V-shaped grooves form a plurality of diamond-shaped protuberances. The diamond-shaped protuberances on one roller being opposite a juncture area between the protuberance on the opposing roller to avoid interference between the destructuring surfaces of the opposing rollers.

We claim: 
     
       1. A chip processing machine comprising: a support frame providing a single swing axis;   two swing assemblies providing parallel side-by-side squeeze rollers, said swing assemblies being swing-mounted on said frame to swing said rollers toward and away from one another on said swing axis between active and inactive positions;   a drive shaft having a rotation axis aligned with said swing axis;   drive assemblies from said drive shaft to said rollers for rotating the rollers in opposite directions at the same rotational speed;   co-acting stops on said swing assemblies for defining the spacing between said rollers when they are in active squeezing position;   a biasing mechanism yieldingly urging said rollers toward one another into active position with said stops in engagement with one another; and   a chute for guiding chips to said rollers to be squeezed therebetween.   
     
     
       2. A chip processing machine according to claim 1 in which said rollers have matching protuberances for fissuring chips passing between the rollers. 
     
     
       3. A chip processing machine according to claim 2 in which said protuberances are formed on each roller by sets of criss-crossing grooves, none of which are parallel with the rotation axis of the roller. 
     
     
       4. A chip processing machine according to claim 1 in which elastic pads are arranged between said support frame and said swing assemblies such that said pads are compressed when said rollers are in active position. 
     
     
       5. A chip processing machine according to claim 1 in which said stops are adjustable to adjust the spacing between said rollers at said active position. 
     
     
       6. A chip processing machine according to claim 1 in which said drive assemblies each comprise a gearbox mounted on the respective swing assembly and having an output shaft connected to the respective roller, each said gearbox having an input shaft coupled by a respective flexible drive from said drive shaft. 
     
     
       7. A chip processing machine according to claim 6 in which each said flexible drive comprises pulleys on said drive shaft and the respective said input shaft, and a timing belt between said pulleys. 
     
     
       8. A chip processing machine according to claim 6 in which one of said gearboxes has an idler gear between its input and output shafts whereby its output shaft turns oppositely from the output shaft of the other gearbox. 
     
     
       9. A chip processing machine according to claim 1 in which each of said swing assemblies comprises two swing arms each swing-mounted at said swing axis adjacent an upper end and providing a bearing for the respective roller adjacent a lower end. 
     
     
       10. A chip processing machine according to claim 9 in which each of said swing assemblies comprises a shaft, a roller on the shall, and two swing arms at opposite ends of the roller and supporting the shaft by bearings, said swing arms being swing-mounted at said swing axis. 
     
     
       11. A chip processing machine according to claim 10 in which said biasing mechanism comprises two hydraulic cylinder units extending between adjacent swing arms of said swing assemblies, the hydraulic fluid at one end of said cylinder units being loaded by compressed gas when said rollers are in active position, said hydraulic units being operable to selectively swing said swing assemblies away from one another to responsively move said rollers into said inactive position. 
     
     
       12. A chip processing machine according to claim 9 in which elastic pads are arranged to be compressed between one end of said swing arms and said support frame when said stops are engaged. 
     
     
       13. A chip processing machine according to claim 1 wherein at least one of said rollers comprises a pair of shaft sections, a support core connected to the shaft sections, and a plurality of curved surface sections removably attached to said support core, said plurality of curved surface sections defining an outer destructuring surface of said roller for destructuring the chips. 
     
     
       14. A chip processing machine according to claim 1 in which each of said rollers have smooth outer surfaces for exerting elevated compressive force on said chips passing between said rollers to create fissures in said chips. 
     
     
       15. A chip processing machine according to claim 1 in which one of said rollers includes smooth outer destructuring surface and the second of said rollers include a plurality of destructuring protuberances for exerting compressive force on said chips passing between said rollers to create fissures in said chips, said destructuring protuberances being formed by sets of criss-crossing grooves, none of said criss-crossing grooves being parallel with the rotation axis of said second of said rollers. 
     
     
       16. A wood chip processing machine for destructuring similarly sized wood chips each having opposite faces separated by a thickness dimension, said machine comprising: a pair of intermeshing rollers, each of the rollers having a destructuring surface defined by a knurled pattern formed by two like sets of equally spaced V-shaped grooves extending helically around the roller and crisscrossing each other at a plurality of junctures such as to form four-sided protrusions each having a peak, each of the plurality of junctures of the crisscrossing V-shaped grooves on each of the rollers being positioned opposite the peak of one of the protrusions on the other roll in the nip where the rolls intermesh, the clearance between the intermeshing rollers at the nip being less than the normal thickness dimension of the chips being processed so that the chips in the nip will be compressed and deformed to destructure the chips, said protrusions being of a size that four of the protrusions on one of said rollers will engage one of said opposite faces of a chip in said nip while a protrusion on the other roller between said four protrusions engages the other of the opposite faces of such chip for assisting in destructuring of the chip while in the nip;   a drive mechanism for turning said rollers on parallel axes at the same rotational speed;   swing arms rotatably carrying said rollers in a side-by-side relationship; and   a frame pivotally supporting said swing arms, said swing arms being pivotal about a common swing axis.   
     
     
       17. The wood chip processing machine of claim 16, further comprising a blocking device coupled to the rollers and positioned to block the rollers from moving past a predetermined position relative to each other to define a minimum clearance between the rollers at the nip. 
     
     
       18. The wood chip processing machine of claim 16, further comprising a movement resistor coupled to the rollers that provides resistance to movement of the rollers away from each other. 
     
     
       19. The wood chip processing machine of claim 16 wherein the movement resistor is a hydraulic cylinder connected to the support arms. 
     
     
       20. The wood chip processing machine of claim 16 wherein at least one of the rollers includes a pair of shaft sections, a support core connected to the shaft sections, and a plurality of surface sections removably attached to the support core, the plurality of surface section defining the destructuring surface of the roller. 
     
     
       21. The wood chip processing machine of claim 16 wherein each of the rollers is coupled to the drive mechanism by a respective drive transmitting device, and the drive mechanism has a drive axis coaxially aligned with the single pivot axis. 
     
     
       22. The wood chip processing machine of claim 16, further comprising a pair of identically ratioed gear reducers, each of the gear reducers being connected to a respective one of the rolls, and each of the gear reducers being connected to the drive mechanism by a respective drive belt such that the drive mechanism simultaneously drives both drive belts and gear reducers for simultaneous rotations of the intermeshing rolls. 
     
     
       23. The wood chip processing machine of claim 16, further comprises a gear reducer connected to each of the rolls and coupled to the drive mechanism, each of said gear reducers is coupled to drive mechanism by a drive transmitting device. 
     
     
       24. A wood chip processing machine for destructuring similarly sized wood chips each normally having four-sided opposite faces separated by a thickness dimension, said machine comprising: a pair of intermeshing like rolls;   a drive mechanism for turning said rolls on parallel axes at the same rotational speed;   each said roll having two crisscrossing like sets of equally spaced V-shaped grooves extending helically around the roll to define junctures at areas where the grooves criss-cross and to define a plurality of protrusions;   each juncture on each of said rolls being positioned opposite the peak of one of the protrusions on the other roll in a nip opening between the rolls where the rolls intermesh, the clearance between the rolls at the nip being less than the normal thickness dimension of the chips being processed so that the chips will be compressed and deformed to destructure the chips;   said protrusions being of a size that four of the protrusions on one of said rolls will normally engage one of said opposite faces of a chip in the nip while a protrusion on the other roll between said four protrusions engages the opposite face of such chip for assisting in destructuring of the chip while in the nip.